Anyone here switch to a mix of lifting and running?

Personally I'd choose between 3 days of compound lifts (squats, deadlifts/pullups, bench press/dips), or some high intensity intervals on the RowErg, SkiErg or bike.

I'd guess that 80% of people who lift do it for the volume alone. 10% do it to become stronger. And the last 10% sums up the rest of the reasons. So unless you wanna walk around in your wifebeater with skinny legs and large (but weak) biceps, go for strength as soon as you're drilled on lifting technique, or you'll be stuck with a lot of useless body mass that ruins your marathon. Lots of people look big and strong, but they're incredibly weak for their weight and/or imbalanced.

I am older (over 60) so what I say may not apply to you. I gave up racing in my mid to later 50's (it was a gradual transition). Now weights are a large part of my exercise regime but I also run, cycle, kayak, hike, swim, cross country ski, do outdoor work and do walks with my wife. Weights you just have to complete whole body workouts including core, arms & shoulders, legs, gluts and balance. I actually actually just do what I am in the mood to do as far as activity and I end doing it regularly.

I have never felt healthier (or looked better) since I gave up beating myself trying for better times or to beat competitors. I thought I would miss the competition, and maybe I did a little bit at first. But I don't at all. Fitness is just much more fun.

I do something similar. I'm a little over 60 years old. Here is what my workouts look like.

ten minute yoga warm up.

short spin

30-45-60 minute daily runs rotating days

30-45-60 minute cycle. long run equals short bike, short run equals longer bike etc

3 days a week, free weight{ nothing heavy} and sit up routine

2 days a week of 30 minute yoga

Best thing I did a year and half’ish back: switched to barely 15 mpw with two days of running + four days of lifting, which I’ve now adjusted to 3 + 3, still with 15-18 mpw; also row and/or cycle once’ish a week.

Cardio more ~3 hours/week is pointless except for fun for non-elites.